Context: Paranasal sinus (PNS) diseases affect a wide range of population and include a broad spectrum of diseases ranging from inflammatory conditions to neoplasms, both benign and malignant. Since their clinical assessment is fraught by the surrounding bony structures; diagnostic radiology is of paramount importance. Aims: This study aims to evaluate the spectrum of PNS diseases on computerized tomography (CT) and correlate their clinical and histopathological findings. Settings and Design: A prospective study one at tertiary care hospital. Subjects and Methods: All patients underwent noncontrast CT (NCCT) of PNSs on multi-detector CT Philips Ingenuity Core 128 multi-slice unit and subsequently underwent functional endoscopic sinus surgery by Hopkins Rod 0° 4 mm endoscope with camera system after that procured specimen was sent for its histopathology. This histopathological diagnosis was correlated with CT diagnosis. Their clinical significance was analyzed statistically. Statistical Analysis Used: All obtained data were compiled in tabulated manner and results were expressed as mean ± standard deviation for the statistical analysis, using Statgraphics Centurion (Version 6.2), Statpoint Technologies, Inc. Virginia 2019. Results: A maximum number of patients were in the age group of 21–30 years. The predominant chief presenting complaint was a headache, followed by nasal discharge. The most common CT diagnosis was chronic sinusitis. Maxillary sinus was the most frequently involved sinus and most common CT inflammatory pattern observed was of sinonasal polyposis. Conclusions: This study proved that CT is an excellent imaging modality for evaluating the normal anatomy, variants, and pathologies of the PNSs with a potential pitfall for the diagnosis of fungal sinusitis.

Paranasal sinuses (PNSs) diseases commonly affect the varied range of population, which range from inflammatory conditions to neoplasms, both benign and malignant.[1],[2]

Their clinical assessment is hampered by the surrounding bony structures, hence for confirmation of their diagnosis, the role of radiology is of paramount importance.[3] Imaging of the sinuses is usually done to approve the clinical findings when history and physical examinations are suggestive of PNS lesions, but the patient is not responding to conventional treatment.

Plain radiography is the commonly used imaging modality for diagnosis of PNS diseases as it is economical, simple, and widely available. However, it only provides a basic overview of the anatomy and underlying pathology. Plain radiography could not display the three-dimensional structures in a two-dimensional plane. It can provides limited views of the anterior ethmoid cells along with the upper two-thirds of the nasal cavity.[4]

Computerized tomography (CT) is considered the gold standard for preoperative evaluation of PNS diseases for appropriate patient selection for functional endoscopic sinus surgery (FESS). It is mandatory to evaluate the PNS and nose by CT before planning for FESS. It can provide a “ROAD MAP” to direct the surgical approach to otolaryngologist. CT has some medico-legal importance as well.[5],[6]

CT plays an important diagnostic role to determine the distribution and extent of paranasal disease and detect those anatomic variations (such as sepal deviation, spur formation, concha bullosa, and paradoxical curve of middle turbinate) that may place the patients at increased risk for intra- and post-operative FESS complications and thereby reduces the morbidity and mortality of patients.[7]

Coronal imaging plane offers the best visualization of the drainage pathways of the sinuses, whereas some drainage pathways (such as sphenoid sinus ostia) and sinus walls, oriented close to the coronal plane, are better seen on axial images.[7],[8]

Contrast enhanced CT scans are obtained only in patients who are acutely ill and suspected of having a complication of acute sinusitis.[9] The present study was aimed to evaluate the spectrum of PNS diseases on CT and correlate their clinical and histopathological findings.

Subjects and Methods

This was a prospective study conducted on 91 patients (from October 1, 2014, to September 30, 2016) after the approval of the Medical Research and Ethical Committee of the Institution.

Both male and female patients of different age groups with clinically suspected PNS diseases were enrolled for the study. All postoperative cases and patients with any traumatic conditions involving PNS were excluded from the study. The detailed clinical assessment was performed, and their informed consent was obtained before subjecting them for the imaging modality.

All patients suffering from sinus diseases, and referred for their diagnostic evaluation, were enrolled for the study. The data of their clinical presentation and of the provisional diagnosis were recorded.

A detailed clinical history including age, sex, occupation, duration of symptoms and specific complaints such as headache, nasal obstruction, nasal discharge, and facial pain were taken. Family history and personal history were also recorded. A thorough clinical examination was done, and obtained data were recorded, and a provisional diagnosis was prepared.

Both axial and coronal images were acquired using multi-detector CT unit.

The sinuses were evaluated for the following parameters: mucosal thickening, wall of sinus, fluid level, soft tissue extension, hyperdensities and masses, blockage of osteomeatal complex, and pattern of bony involvement.

The results were recorded and expressed as sinus distribution, side of involvement, frequency of deviated nasal septum (DNS), concha bullosa, frequency of ostemeatal unit involvement, and provisional CT diagnosis.

Results

FESS was done in all patients in and biopsy specimen was taken for histopathological evaluation. The clinical, CT and histopathological diagnosis were recorded for their correlation and data analysis.

A total of 91 patients fulfilling the inclusion criteria, were included in the present study. A descriptive comparative analysis of imaging findings was conducted, tabulated, and results were derived.

The majority of the cases were in the age group of 21–30 years (33%) and least number of patients were in age group of 71–80 years (0.76%). The youngest patient was 8-year-old, and eldest patient was 72-year-old. There was a male predominance of 56.2% (73/130) as compared to females 43.8% (57/130). The male to female ratio was 1.3:1. The chief presenting complaint was of a headache (67.7%) followed by nasal discharge (40.8%), nasal obstruction (42.3%), facial pain (33.8%), and others (37.7%).

Figure 5: Axial noncontrast computed tomography image in bone window showing a mass causing opacification of left maxillary and ethmoid sinus with erosive destruction of adjacent walls of the sinuses and is seen extending into left pterygopalatine fossa and nasal cavity

High sensitivity, specificity, positive and negative pedictive values were noted in all diagnosis except fungal sinusitis which revealed a sensitivity of 66.6%, a specificity of 91%, a positive predictive value of 46.1%, and negative predictive value of 96.1% [Table 3].

In this study, maxillary sinus (83.5%) was the most commonly involved sinus followed by ethmoid sinus (74.7%), sphenoid sinus (43.9%), and frontal sinus (54.9%). DNS was noted toward right side in 43.9% cases and toward left side in 28.5% of cases. Concha bullosa was noted in 39 (30%) cases of which left sided involvement was noted in 17 (13.05%%), right siuded in 14 (10.8%) and bilateral in 8 caess (6.92%) [Figure 7],[Figure 8] and [Table 4],[Table 5].

Ostiomeatal unit (OMU) obstruction was noted in 49 cases (53.8%), of which left sided was noted in 26.3%, right sided in 24.1%, and bilateral involvement was seen in 3.2% cases. The most common pattern of involvement was sinonasal polyposis (41.7%), followed by osteomeatal (28.5%), infundibular (15.3%), sphenoethmoidal recess (5.4%), and sporadic pattern (2.1%) [Figure 9], [Figure 10], [Figure 11], [Figure 12], [Figure 13] and [Table 6],[Table 7].

The present study has evaluated the imaging spectrum of PNS diseases on CT and correlated its diagnostic accuracy with histopathology. A total of 91 patients, who fulfilled the inclusion criteria, were included in the present study.

The majority of the cases were in the age group of 21–30 years (33%) and least number of patients were in age group of 71–80 years (0.76%). There was a male predominance of 56.2% (73/130) as compared to females 43.8% (57/130). The male to female ratio was 1.3:1. The demographic distribution of the present was in concordance with other studies, done by Venkatachalam and Bhat,[10] Prabhakar et al.,[11] Gliklich and Metson,[12] Dewan et al.,[13] Ahmed et al.[14] and Chakraborty et al.[15]

The chief presenting complaint was of headache (67.7%) followed by nasal discharge (40.8%), nasal obstruction (42.3%), facial pain (33.8%), and others (37.7%). Kushwah et al.[16] Asruddin et al.[17] and Dewan et al.[13] also noted similar findings their studies. They all concluded that a headache was the predominant presenting complaint.

In the present study, maxillary sinus (83.5%) was the most commonly involved sinus followed by ethmoid (74.7%), sphenoid (43.9%), and frontal (54.9%). Kushwah et al.,[16] Chaitanya et al.,[18] Zinreich,[4] Bolger[19] and Maru and Gupta[20] noted similar results in their studies.

OMU obstruction was noted in 49 cases (53.8%), of which left sided was noted in 26.3%, right sided in 24.1%, and bilateral involvement in 3.2% cases. Kushwah et al.,[16] Dua et al.[21] and Yousem[22] reported similar findings.

Most common pattern of involvement was sinonasal polyposis (41.7%) followed by osteomeatal (28.5%), infundibular (15.3%), sphenoethmoidal recess (5.4%), and sporadic pattern (2.1%). Chaitanya et al.[18] and Kushwah et al.[16] noted similar distribution in their studies.

DNS was noted toward right side in 43.9% cases and toward left side in 28.5% of cases. Concha bullosa was seen in 39 cases (30%), of which left-sided involvement was noted in 17 cases (13.1%), right sided in 14 cases (10%), and bilateral in 8 cases (6.2%). These findings correlate well with results of Asruddin et al.,[17] Maru and Gupta,[20] Ahmed et al.[14] and Chakraborty et al.[15]

In the present study, the most common CT inflammatory pattern was the sinonasal polyposis in 38.7% cases (48/124) followed by osteomeatal pattern in 28.2% cases (35/124), infundibular pattern in 20.1% cases (25/124), sphenoethmoidal recess pattern in 8% cases (10/124), and sporadic pattern in 1.6% cases (2/124). Chaitanya et al.[18] reported that the sinonasal polyposis pattern was the most common followed by OMU, infundibular, sphenoethmoid recess, and sporadic patterns in decreasing order of involvement.

In the present study CT, detected bone involvement, i.e., erosion or destruction of sinus walls in six cases (4.6%) while clinically, no bony involvement was detected in these cases. Kushwah et al.[16] also reported similar findings in their study.

In the present study, a good correlation was noted in cases of chronic sinusitis, polyps, antrochoanal polyps and neoplasms, as evidenced by high sensitivity and specificity values in cases of chronic sinusitis (97.7% and 97.8%), polyp (95% and 98.5%), antrochoanal polyps (100% and 98.8%), and neoplasm (100% and 97.7%), respectively. However, poor correlation was noted in cases of fungal sinusitis which was supported by the low sensitivity of 66.6%. Similar results were noted when the positive and negative predictive values were calculated for all diagnosis.

In the present study, CT reported 16 cases as fungal sinusitis, out of which only 6 cases were confirmed by histopathology. This high mismatch was noted due to 7 cases being reported as falsely positive as a result of high density or inspissated secretions, noted in these patients. Kushwah et al.,[16] Zenreich et al.[4] and Chaitanya et al.[18] also reported similar findings except for fungal sinusitis, where sensitivity and specificity of CT was almost 100%.

Conclusion

CT was able to characterize the PNS diseases along with their extension. It could also delineate the bony involvement of PNS diseases. Preoperative CT enabled the surgeon to visualize the drainage pathways, anatomical and critical variants in PNSs thus allowing effective management of the patient. However, a potential pitfall was its inability to accurately differentiate in cases of fungal sinusitis and high-density secretions. CT may be used as gold standard imaging modality for evaluating the PNS diseases.